1. Field of the Invention
This invention generally relates to the encryption of digital information, and more particularly to a system and method for controlling access to encrypted audiovisual, textual, and other digital information on a host computer system. The invention is also a business method based on this access control method.
2. Description of the Related Art
The ubiquitous appeal of computer networks has greatly simplified the dissemination of information. Through the internet, for example, digital images, movies, and text-based files can be downloaded to host computer systems in mere seconds. The availability of this information has spawned entire industries dedicated to compression technologies for making these downloads faster and more efficient, encryption technologies for making them more secure, and e-business technologies for selling information to consumers.
The implementation of these e-business practices is not without problems. One significant problem focuses on providing information to customers in a way that allows the e-business to make a profit. A typical scenario involves a company which provides JPEG or MPEG files to the public. These files may be personalized to the user. For example, the business may have acquired image files of a customer's newborn baby while at the hospital. Now, the business seeks to sell these pictures. Employing conventional methods, the business may send one of the images to the customer as a promotional incentive. This approach is undesirable because if the customer does not make a purchase, the business has essentially given the customer an image free of charge.
Other conventional techniques involve making a non-downloadable sample picture available on a website secured by a dated password, i.e., the customer may view the image on the provider's website using a password that is operative for a limited period of time. This approach requires a great deal of effort by the business and is not secure because, while the file may not be in downloadable form, the customer may still obtain the images free by capturing bitmaps of them. Further, such an approach is vulnerable to skilled hackers who have the ability to breach the security provided by the password scheme.
In view of the foregoing considerations, it is clear that there is a need for an improved system and method for controlling a user's access to digital information, and moreover one which provides access to at least a sample of the digital information without compromising the ability of the business to make a profit. There is a further need of providing such a system and method with tamper-resistant features and which operates in a manner which enhances convenience to both the user and provider.